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Layers in VEA |
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Visio Tool Tips
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By Scot Becker on
5/4/2005
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Visio has a generic layer facility that allows you to place shapes on one or more layers. A user can then specify settings for a given layer that dictate some behavior for all shapes on that layer.
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New Site Coming Soon! |
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Site Announcements
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By Scot Becker on
3/23/2005
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Just a quick note to let everyone know that I am in the process of re-vamping objectrolemodeling.com to include more (interactive) content, a different underlying framework, and switching ISPs.
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ORM Webcast |
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News
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By Scot Becker on
12/29/2004
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SearchDatabase.com has a webcast featuring Terry Halpin titled "Fact-based Database Design".
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Nested Role Readings |
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Visio Tool Tips
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By Scot Becker on
11/3/2004
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You may have noticed than when an object type is the result of a nested predicate, you can specify extra information on the "Nested Roles" tab of the "Database Properties" window. This is provided in case you wish to add extra semantics between the relationship of the nested object type and the object types that make up the fact type that was nested.
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User Defined Types and ORM |
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Visio Tool Tips
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By Scot Becker on
11/2/2004
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User defined types are typically used to express semantic domains that cross multiple attributes. For example, one could create a type named "Phone Number" as some sort of length-limited character type and then use that type as the basis for several attributes such as fax number, mobile number, office number, home number, and so on.
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Visio FAQ: Ordering columns in index creation |
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Visio FAQ
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By Scot Becker on
10/22/2004
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In some DBMS’s, the order in which columns appear in the creation/definition of an index (which spans multiple columns) can have performance impacts. Should you be saddled with such a silly restriction, you might be wondering how to specify the column order within Visio.
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N-ary fact verbalizations |
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Visio Tool Tips
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By Scot Becker on
10/20/2004
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For any given fact type, there are n! (read: n factorial) readings of that fact type (where n is the number of roles in the fact type). In a unary fact type, there is exactly one reading, in a binary there are two readings, in a ternary there are six readings (3 x 2 x 1), in a quaternary there are 24 readings (4 x 3 x 2 x 1), and so on.
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Using Namespaces in ORM Source Models |
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Visio Tool Tips
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By Scot Becker on
10/14/2004
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Many object types have similar (usually, descriptive) properties. For example, People, Animals, Products, and so on, all have names. This poses a choice for the ORM Modeler: do you create one "Name" object type or multiple?
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